Impulse-transmitting device.



A. E. KEITH. v IMRQLSE TRANSMITTING DEVICE.

. APPLICATION FILED MAR. 3. I913- 1,209,804., Patented De0 19,]916. 2SHEETSSHEETI W/TNE A. E. KEITH. IMPULSE TRANSMITTING DEVICE. APPLICATIONFILED MAR. 3. ms.

Patented Dec. 19, 1916.

2 SHEETS-SHEET 2.

J/VJTNESSES WEED %TAT% FA Fll@.

ALEXANDER E. KEITH, 0F HINSDALE, ILLINOIS, ASSIGNOR TO AUTOMATICELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

IMPULSE-TRANSMITTING DEVICE.

Application filed March 3, 1913.

TQ all whom it may concern Be it known that I, ALEXANDER E. KEITH, acitizen of the United States of America, and resident of Hinsdale,Dupage county, Illinois, have invented certain new and usefulImprovements in Impulse-Transmitting Devices, of which the following isa specification.

My invention relates to impulse-transmitting devices, and relates moreparticularly to an impulse-transmitting device for use by an operator ina semi-automatic telephone system, although, of course, if desired thisimpulse-transmitting device can be employed at a substation in anautomatic or semi-automatic telephone system.

Among the objects of my invention are to provide an impulse-transmittingdevice which enables an operator to set up the call as rapidly aspossible, and to provide means whereby the impulses are transmitted at auniform speed and are properly spaced.

More specific objects of my invention are the provision of a pluralityof impulse senders, preferably one for each digit of the called number,and a plurality of keys associated with each of said impulse senders,which keysvariably operate said impulse senders in accordance with thedigit of the called number. Further objects are the provision of meansto prevent the second impulse sender from operating until after theimpulses from the first sender have been transmitted, and to likewiseprovide means for properly spacing apart the impulses from the first andsecond senders. 7

These and other objects of my invention will be more readily understoodby reference to the accompanying drawings, in which- Figure 1 representsa front side view of an impulse-transmitting device embodying thefeatures of my invention, showing certain parts removed so as to moreclearly show the interior construction and showing three calling devicesX, Y and Z. Fig. 2

is a back view of a portion of the same.-

3 is a section taken on line 3-3 in Fig. 2. Fig. 4 is a diagrammaticcircult view of the whole device.

Specification of Letters Patent.

Patented Dec. 19, 1916..

Serial No. 751,873.

The calling device X is shown as it appears complete, with a circularplate A and a plurality of push buttons or keys 4, the shafts 3 (Fig. 3)of which protrude through the plate A. A plurality of pairs of contactsprings 5 and 6 corresponding to the keys of the calling device aremounted on the under side of the plate A and are secured thereto bymeans of a screw 7. The keys 4, after having been depressed, may berestored in any suitable manner, as, for example, by the provision of acoil spring underneath each key, or by the springs 5 and 6 themselves.The second calling device Y is shown with the plate A removed, but withthe springs 5 and 6 showing against another plate B, which plate isfastened to the plate A by means of screws and posts 17. The thirdcalling device is illustrated with both .the plates A and B removed,showing a third plate C through. which projects a shaft 20, to the endof which shaft there are secured a disk 12 and an arm 13. These callingdevices are mounted on a base plate F, and Fig. 2 shows the assembly ofone of the calling devices at the back of said base plate, together witha solenoid D which, when energized, attracts its plunger 8, and by meansof a link 9 operates the lever 19 against the tension of the spring 21.On the end of the lever 19 is the segment of a gear wheel 10 in meshwith a gear wheel 11. The gear wheel 11 is attached to the shaft 20, towhich the disk 12 is secured in front of the plate C. The'shaft 20 isjournaled at one end in a bridge-piece 22 and at the other end in theplate C. To the under side of the disk 12 is attached a pawl 23, itsfunction being to engage with the ratchet wheel 24 which is attached tothe gear wheel 15. This gear wheel is loosely mounted on the shaft 20and is in mesh with a smaller wheel 16 which is on the same shaft as theimpulse cam 43 and the wheel 44 that operate in connection with thegovernor 25. To each of the second and third calling devices there isassigned a magnet 18 mounted on the rear of the keyboard. Each of thesemagnets is provided with an armature 26 and spring 28, the end of whichlatter is turned up in such a manner as to arrest the revolving of andmake contact only when the solenoid D is energized.

Having given a detailed description of the component parts, I will nowdescribe the mechanical operation, referring more particularly .to thediagrammatic showing in Fig. 4. As has been stated heretofore, there ismounted on one base plate a plurality of calling devices. There arepreferably as many of these calling devices as there are digits in thetelephone numbers in the system in which the keyboard is to be used. Inthe accompanying drawings there are shown three such devices. Theimpulse springs 30 of the three calling devices are connected in series,as shown in Fig. 4. We will assume that the operator wishes to call thenumber 678. She therefore pushes the keys No. 6 of the device X, No. 7of the device Y and No. 8 of the device Z in quick succession. Thisoperation presses together one of the pairs of springs 5 and 6 ofeachcalling device and energizes their respective solenoids D overcircuits extending from ground G through said solenoids D and throughthesprings 5 and 6, corresponding to the keys pressed, to thenon-grounded terminal of the battery H. Upon the energization of thesolenoids the plungers are pulled up, revolving the shafts 20 until theyare stopped by the arms 13 coming into contact with the shafts 3 of thekeys just depressed, whereby the ratchet 23 of each calling device willbe advanced past a number of notches in the wheel 24, corresponding tothe button pressed. The keys 4 are provided with a long stroke and afterthey have been pressed to the full length of their stroke are restoredby the tension of the springs 5 and 6, as before pointed out. Thesprings 5 and 6 are arranged to make contact on the initial downwardmovement of the key and to break on the return of the key to normal,just before the extension 3 is removed from the path of the arm 13.Therefore, When-- just beforethe extension 3 is removed fromthe path ofthe arm 13, thereby preventing the further rotation of the same. Thesolenoid of the calling device whichwas operated for the first digit,upon deenergizing, immediately commences to return to its normalposition. As the plunger 8 returns to its normal position, said ratchet23 engages with the notch in the ratchet wheel 24 to which said ratchetwas advanced by the energization of the solenoid and-forces the wheel 24to rotate back with the shaft 20.

Through the medium of the spur teeth 15 and pinion 16 this rotation istransmitted to the shaft on which is fastened the impulse cam 43. Thecam 43 revolves to open and close the springs 30 six times, sending thatnumber of impulses over the line to operate the central ofliceapparatus. As heretofore stated, there is a wheel 44 on the same shaftas the cam 43 which is in connection with tery H. WVhen the plunger ofthe solenoid of the firstcalling device reaches its normal position itseparates the springs 31, opening the circuit of the magnet. 18 of thesucceeding calling device. The magnets 18 are preferably slow actingthatis, sloW to deenergize-so as to cause an appreciable interval of time toelapse between the completion of the operation of one calling devlce andthe beginning of the operation of the next one. This interval is usuallynecessary in order to give the central oflice apparatus sufficient timeto perform certain operations, such as selecting idle trunk lines, etc.,after operating in response to the numerical 1mpulses for each digit.Upon the deenergization of the magnet 18 of the second calling device,its solenoid D and the shaft 20 are permitted to return to normalposition, during which operation the cam 43 separates the springs 30seven times to transmit the seven impulses for the second digit over thehue. When the plunger of the solenoid of the second calling devicereaches its normal position it breaks the circuit of the magnet 18 ofthe third calling device, which releases the mechanism and allows it torestore to normal position, whereby the eight impulses lfgr the lastdigit are transmitted over the e. It will thus be seen that I haveprovided a very efficient form of calling or impulsetransmitting devicein which the operator can set up the call by operating the various keysof the separate calling devices, but the impulses transmitted over thewire are at all times so controlled that they are transmitted at auniform speed and are properly spaced apart so as to secure the properoperation of the automatic switches with which this callsending devicewill be associated.

While I have illustrated and described one embodiment of my invention,it is to be understood that I do not wish to be limited to the exactconstruction shown and described.

What I claim as my invention is 1. In an impulse-transmitting device, aplurality of impulse senders, electro-mechanical means for operatingsaid impulse senders, and a plurality of keys associated with eachsender for variably placing said operating means in condition tovariably operate the respective impulse senders, depending upon the keyoperated, whereby said impulse sender may transmit a variable number ofimpulses.

2. In an impulse-transmitting device, a plurality of impulse senders,electro-mechanical means for operating said impulse senders, a pluralityof keys associated with each sender for variably placing said operatingmeans in condition to variably operate the respective impulse senders,depending upon the key operated, whereby each impulse sender maytransmit a variable number of impulses, and means for preventing morethan one of said impulse senders from operating at a time.

3. In an impulse-transmitting device, a plurality of impulse senders,means for operating said impulse senders, a plurality of keys associatedwith each sender for variably placing said operating means in conditionto variably operate the respective impulse senders, depending upon thekey operated, whereby each impulse sender may transmit a variable numberof impulses, and means for preventing the second of said impulse sendersfrom operating until a predetermined time after said first impulsesender has completed its operation.

4. An impulse-transmitting device comprising a series of impulsesenders, means for operating said impulse senders, a series of keysassociated with each of said senders for variably placing said operatingmeans in condition to variably operate said impulse senders whereby eachsender may transmit a variable number of impulses, and means permittingsimultaneous operation of said keys but preventing simultaneousoperation of said impulse senders.

5. An impulse-transmitting device comprising apluralityof impulsesenders, means for operating said impulse senders, a plurality of keysassociated with each of said senders, means controlled by said keys forvariably placing said operating means in condition to operate saidsenders, whereby each sender may transmit a variable number of impulses,and means for preventing .simultaneous operation of tWo of said impulsesenders.

6. In an impulse-transmitting device, a plurality of impulse senders,each of said impulse senders including a pair of impulse springs, aratchet mechanism for operating said springs, a pawl adapted to berotated around said ratchet in one direction without operating saidratchet, and adapted to operate said ratchet upon the return movement ofsaid pawl, a magnet for controlling the first movement of said pawl, aspring for controlling the return movement, a plurality of keys forvariably operating said magnet operate said ratchet upon the returnmovement of said pawl, a magnet for controlling .the first movement ofsaid pawl, a spring for controlling the return movement, a plurality ofkeys for variably operating said magnet to control the extent ofoperation of said pawl, and means for locking the pawl of the secondimpulse sender against return movement until after the previous impulsesender has completed its operation.

8. In an impulse-transmitting device, a plurality of impulse senders,each of said impulse senders including a pair of impulse springs, aratchet mechanism for operating said springs, a pawl adapted to berotated around said ratchet in one direction without operating saidratchet, and adapted to operate said ratchet upon the return movement of.said pawl, a magnet for controlling the first movement of said pawl, aspring for controlling the return movement, a plurality of keys forvariably operating said magnet to control the extent of operation ofsaid pawl, and means including a slow acting relay for locking the pawlof the second impulse sender until after the first impulse sender hascompleted its operation.

9. In an impulse-transmitting device, a series of sets of keys, animpulse controller for each set, an automatically movable member foreach controller, means associated with each set for moving the movablemember of its controller a variable distance to determine how manyimpulses will be trans- Signed by me at Chicago, Cook county,

mitted before said impulses are transmitted, 7 Illinois, this 24th dayof February, 1918. each impulse controller having means to ALEXANDER E.KEITH. lock the next one in the series, and means Witnesses:

5 for unlocking the locked controller When the H. KNUnsoN,

one looking it has completed its operation. J. NORBY.

